Do you know what entices your girlfriend to have sex with you? Is it love, desire, money, power, alcohol or even pity? Psychologists at the University of Texas at Austin decided the topic was meaty enough to write a book about. Why Women Have Sex was published in September and its writers cobbled together hundreds of hours of scientific research to try and come up with a reasonable thesis on the matter. As it turns out, women have sex for a variety of reasons; unfortunately for the male ego, it’s not always because of passion.

In a study conducted over almost three years (June 2006 to April 2009), about 1,000 women were asked why they had sex, and given 237 different reasons to choose from. The results showed they did it for gifts, boredom, jealousy, a sense of duty, to get rid of headaches and many, many more reasons. In fact, their motives were so wide-ranging the real news was that the sex was often about anything other than passion. Ouch. The crack research team also uncovered groundbreaking discoveries like there are many more factors contributing to women having sex than there are for men, and the act of sexual arousal is much more complicated for women. It took three years to figure that out?

Regardless of how many copies are sold, you know some guy is already working on a follow up to Why Women Have Sex, and you can bet it won’t require three years of research, either. With the working title: Because It’s Awesome, it will likely be a quick read.